Process for quick drying of clay articles



Patented Dee. 23, 1924,

ROBERT N. CHAPMAN,

i TEN'l' ()FFICE,

OF DUBLIN, GEORGIA.

PROCESS FOR QUICK DRYING OF CLAY ARTICLES.

1T0 Drawing. Application filed May 21,

T all whom it may concern:

Be it known that I, ROBERT N. CHAPMAN,

a citizen of the United States, residing at Dublin, in the county of Laurens and State 5 of Georgia, have invented certain new and useful Improvements in a Process for Quick Drying of Clay Articles; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to processes used in forming dried clay articles preparatory to burning.

Heretofore, it has been the general practice to mix the clay with cold water to form the mud from which the bricks or other articles are molded and when this has been done, the drying of the articles cannot in reality begin until .they have set up, that is reached suflicient temperature to prevent them from sticking to each other and clinging to the pallets upon which they are supported. If any large amount of heat is applied before this setting up takes place, the articles will crack and it is therefore necessary to allow the product to stay in the drying house at a very low temperlature for many hours before the temperature is raised sufficiently to produce any appreciable drying. This old process requires anywhere from twelve to seventy-two hours, but it is the object of my invention to provide an improved process which will enable the clay articles to be inserted into a hot drying chamber, without any danger whatever of checking or cracking, the improved process being such that the ware may be elficiently dried in a very few hours.

Briefly speaking, I form a preferably hot mixture of clay and water, add a hotfilling of sand, loam, ground clay, etc., form the articles from this mixture while it is hot, and place such articles while they remain heated, in a drying house or tunnel which has been previously heated to such an extent as to cause the drying operation to start immediately.

In darrying my process into effect, I prefer to make use of an ordinary pug mill or other mixing machine having sufficient pugging facilities. This machine is pref 1923. Serial No. 640,609.

erably provided with a cover to prevent loss of heat. The clay as it comes from the mine,

is fed into the rear end of the machine and hot water is added, thus not only forming mud but serving to temper it much more effectively than cold water. A suflicient distance down the mill to permit the proper mixing and tempering of the mud before this point is reached, I add hot sand or any other desired hot filling, in the proper quantity, according to the character of the clay and the articles to be produced. This hot sand or other filler, when poured into the pug mill is thoroughly mixed with the hot clay mud, greatly increasing the temperature of the latter and serving to still more effectively temper the same.

The mixture of hot water, hot clay and hot filling, is carried forward in the pug mill until the brick molding machine or other article forming means is reached. Here the mixture is formed while hot into iarticles of desired shape and these articles while still at a high temperature, are placed in a hot drying room or tunnel. If molds are used in forming the articles and they usually are, I subject them to a spray of steam or hot water before filling, for the purpose of preventing any of the hot mix ture from clinging to the mold w alls.

If a drying house is used having the usual steam pipe rack upon which to stack the articles to be dried, it has been customary to rack all of these articles while the pipes are cold. This has been necessary in order that the temperature of the pipes shall substantiate that of the articles. Then, when the racks have been filled, it has been customary to turn on a very low steam pressure to merely warm the pipe racks, giving time to heat the articles thoroughly before the real drying heat is turned on. Twelve hours is considered very rapid drying by this process.

In carrying out my process, I heat the pipe racks from 40 to C. and the brlcks or other articles are stacked upon them at approximately the same or even a higher temperature, thereby saving a number of hours over the old method, as it is unnecessary to slowly heat the bricks or the like before the drying operation commences.

which the mixing machine or pug mill is located, is preferably much higher than is required when steam pipe racks are used for drying, as a good deal of time is necessary in stacking the bricks or the like upon the cars which carry them through the tunnel and hence some loss of heat takes placeduring this operation. The first few cars of brick should enter the, tunnel at about an even temperature with the latter, but after the tunnel has been maintained at this heat for sometime and the bricks have been fed into the same, the temperature may be safely increased to a great deal more than the temperature of the ingoing brick, on account of the fact that the preceding brick have caused a hot vapor to rise and the new brick are met by this moisture which en ables them to stand a greater temperature than if entering under other, conditions.

It is preferable that the tunnel or tunnels shallbe so arranged that the brick or the like can enter at a temperature of from 50 to 80 C. and arranged so the cars of brick can pass down the tunnel or tunnels at a gradual rise of temperature until the end of the tunnel is reached in three. to five hours, at which time, the outletend of the tunnel preferably has a temperature of from 150 to 200 C. The rapidity with which the temperature in the tunnel can be raised is generally controlled by the amount of sand or other hot fillerwhich is added to the mud.

In the foregoing, I have described the soft mud method of forming the articles. In carrying out the stiff mud process, about the same conditions apply, except that the mixture is made stiffer and cannot carry as high a temperature, owing to the fact that off-bearers cannot handle the product at so high a temperature. I Q

It will be seen from the foregoing that my improved process possesses the advantages of producing better articles, more uniform articles and more rapid drying. Furthermore, night drying is unnecessary with the new process,the number of'pallets, and drying cars is reduced greatly and the area of the drying house or the like may be greatly reduced, thereby effecting tremendous savings in the manufacture of brick and other clay articles.

I have described the preferred manner of carrying out the improved process, 'but'it is to be understood that within the scope'of theinvention as claimed, min or changes may be made. For instance, it is not always essential that the clay be mixed with hot water before addition of the hot filling, as cold water may be used at times if desired. The hot water however, is preferable.

g It may be further stated that by carrying out my process, mud which is too soft or thin to be made into brick, can be converted into the proper consistency by addition of the hot filling. Attention-may also be directed to the fact that products made by my improved process, when dried otherwise than artificially, produce better articles than those produced by ordinarymethods, owing to the fact that the mud is tempered much better than ordinarily.

I- claim:

1. The process of forming dried clay articles, consisting in mixing a hot filling with a mixture of clay andfwater to heat and temper the mixture, formingthe mixQ ture while heated into articles 'of 'desired form and placing such articles while heated in a heated drying chamber.

2. The process of forming driedclay articles, consisting in mixing a hot filling with a hot mixture of clay and water to heat and temper the mixture, formingthemixture while heated into. articles of desired form, and placing such articles while heated in a heated'drying chamber. I

3. The process of forming dried clay articles, consisting in mixing clav with hot water to form mud. mixing a hot filling with the mud, forming this mixture while hotinto articles of desired shape,. and placing such articles while hot in a hot drying chamber,

4. The process of forming dried clav articles, consisting in mixing hot sand with a mixture of clay and water to heat and temper the mixture, forming this mixture while heated into articles of desired'shape,

temper the mixture. forming this mixture while heated into articles of desiredfshape, and placing theartieles while heated in a heated drying chamber.

6. The process of forming dried 'ielay articles consisting in mixing clav with hot water to form mud, mixingv hot sand with the mixture of clay and water. forming this mixture while hotinto articles of desired.

shape, and. placing such articles while hot in a hot drying chamber. k r

7. The process of forming 'dried 'clay articles. consisting in mixing a hot filler with ,a hot mixture of water and clay,

dampening a mold, molding the mixture while hot in the dampened mold, and placing the molded articleswhile hot in a hot dry ing chamber. v.

The process of: forming dried clay articles consisting in mixing at hot filler with 21 hot mixture of Water and clay, subjecting the interior of a mold to steam, molding the mixture While hot in the dampened mold, and piecing the molded article in a hot drying chamber.

9. The process of forming dried clay articles, consisting in mixing a hot filling With a mixture of clay and Water to heat and temper the mixture, forming the mixture while heated into articles of desired forms, and drying the heated articles.

In testimony whereof I have hereunto affixed my signature.

ROBERT N. CHAPMAN. 

